Screw-making machine.



l F. 0." CURTIS. sonnw MAKING MACHINE. APPLICATION FILED s112123; 1907.

905,991. f Patnd Dec. 8, 1908.

F. vo. CURTIS. l SCREW MAKING MACHINE.

APPLICATION FILED SEPT.3, 1907.

905,991. Patented De0.8,19os.

2 SHEETS-SHEET 2.

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me Natexis PETERS co., wAsmNcToN. D. c.

`PATENT OFFICE.

FRANK O. CURTIS, OF BUFFALO, NEW YORK.

SCREW-MAKIN G MACHINE.

Specification of Letters Patent.

Patented Dec. 8, 1908.

i Application led September 3, 1907. Serial No. 391,205.

To all whom it may concern: Y Be it known that I, FRANK O. CURTIS, -acitizen of the United States, and resident of Buffalo, Erie county,State of New York, have invented certain new and useful Improvements inScrew-Making Machines; and my preferred manner of carrying out theinvention is set forth in the following full, clear, and exactdescription, terminating with claims particularly specifying thenovelty.

This invention consists more particularly in improvements on my formerpatent in the same line, numbered 712506 and issued November 4, 1902;and the object of the present invention is to simplify the formerconstruction in certain respects and increase the output of the machine.This object l accomplish by connecting the die-spindle-sleeve with thepower shaft by a retarding device including differential gears andratchet teeth between the gear on the shaft and a collar ixed thereon,and thus causing the die spindle to revolve in the same direction as,but more slowly than, the live s indle While the screw is being cut,after whic it revolves in the same direction and quite rapidly in orderto draw the die off of the finished screw. Hence the die can be runslower and the machine faster and its output correspondingly increased.

ln the accompanying drawings-Figure 1 is a front elevation of thismachine with the live spindle head partly in' section and the diespindles omitted; Fig. 2 is an enlarged rear elevation of one diespindle, its guide, and the mechanism for operating it; Fig. 3 is alongitudinal sectional view of the same with the parts in a differentposition; Fig. 4 is a cross section on the line 4 of Fig. 2; and Fig. 5is an enlarged detail,

In the said drawings the numeral 1 designates the base of this machinein which is mounted the main shaft 2, the latter receiving power from abelt leading to a Wheel 4 connected to the said shaft by a worm 5 andworm wheel 6. Upon the base is supported the bed 10 carrying the variousparts of the machine. On this shaft is mounted a driving gear 30,meshing with a smaller gear 31 on a counter-shaft 32, mounted inbearings in the bed 10, and this counter-shaft carries a larger gear 33,which extendsl upward through the case 35 of the live-spindle head 34and engages teeth 36 thereon. Such head turns within the case, and inthe present machine it is constructed like a spool in whose ends arefixed boxes 37, in which are mounted live-spindles 38, each having achuck 39, as usual. The spindles are turned by power applied to a pulley130 on a power shaft 131 which leads through the hub of the spindle head34 and carries a gear 41, the latter meshing with a planetary series ofgears 43 of which each has a collar 44 for turning its spindle withinits box.

Suitable mechanism (not shown) is employed for locking and releasing thehead 34 within the case 35 at proper times; and this mechanism isoperated by a lever 72 leading downward through the case and moved by acam face 71 on a disk 70 which is mounted on the main shaft. Cut-offknives 202 are mounted in guides 203 on the bed, and operated at ropertimes by levers 201 which are tripped y a cam or cams 200 on the mainshaft. The dead or tool spindles 81 and 82, and a third member which isa stop 83, are held by set screws 92 in a slide 80 which is mounted forlongitudinal reciprocation on the bed and guided thereon by a track 86which may have gibs 87 The mechanism for moving this slide consists of acam 100 having cam faces 101 between which stands a roller 102 at thelower end of a bolt 103 in the slide 80 and passing through a slot inthe bed. 110 is a cam wheel fast on the shaft 2 and having acam face 111on its periphery roperly located to strike a roller 112 on the .lever113 pivoted at 114 to the bed. The upper end of this lever is pivoted at115 to a fork 116 which loosely engages a groove in a clutch member 128;and the roller is held against the cam by a spring 120 which here leadsto one of two standards 118. Mounted for longitudinal and rotarymovement in the standards is a die spindle 121 having a die holder 122at its inner end. Near the latter the spindle extends loosely through along sleeve 123, and the sleeve passes through the inner standard 118and has an integral head 124 at its inner end. Upon the other end ofthis sleeve is secured a gear 150 whose hubl of the spindle 121 betweena shoulder 142 and a collar 138 which ermit slight longitudinal movementof sai gear. Continuing through said standard, the reduced portion ofthe spindle is surrounded by a spring 140, exerting expansive forcebetween the said standard and a collar 141 at the extreme end of thespindle, and having a tendency to hold the latter normally retractedwith the shoulder 142 against the gear 134 and the latter against thestandard 118, while the collar 138 is drawn into a cavity 139 in saidstandard. Gbviously, if the spindle is moved inward the collar 138 willcause the gear 134 to move with it and the length of the drum gear 133will prevent the cessation of rotation. In the adjacent faces of theholder 122 and the sleeve head 124 are pins 143 having inclined engagingfaces. The retarding device comprises the large gear 150 meshing with along gear 151 mounted loosely on the shaft 131 and having a shoulder 152which enters a pocket 153 within the drum gear 133 and rests against anexpansive spring 154, the latter thereby holding the shoulder againstsaid gear 150; a collar 155 fixed on the shaft 131 beyond the other endof the long gear 151; and ratchet teeth 156 in the adjacent ends orfaces of the collar and long gear.

W ith the above construction of parts and about five spindles 38 (whichis the number l prefer) within the head 34, the operation of my machineis as follows, the parts being properly shaped and timed so as toperform their functions in correct relation to each other and powerbeing applied at 4 and 130, as above indicated: Bars of iron, formingthe stock from which the screws are to be made, are inserted from theleft in Fig. 1 one at a time through the empty spindle 38 4as it ismoved by the turning of the head 34 to the lowermost position, and eachbar is then pushed inward until its inner end strikes the stop 83, whichpermits the bar to project beyond the clutch 39 for just a distancewhich will be the length of the finished screw. It is understood thatthe contour of this bar is that of the head of the finished screw, whichobviates the necessity for doing more with my machine than turning thebody of the screw, threading it, and then severing it with its head fromthe stock remaining and it is also to be understood that the stock-baris loosened and tightened in the chuck 39 on the lowermost spindleeither by hand or by mechanism forming no part of the present invention,and therefore, not illustrated and described herein. I have also notshown the roughing-tool which is mounted in the lowermost tool-holder,nor the finishin tool which is mounted in the u permost too -holder 94.These turn out the iibdy of the screw. Nor have I shown the first andsecond dies, which are mounted, respectively, in the upper and lowerdie-holders 122 and cut the thread u on said body; but it will be clearthat as t e blank progresses under the turning of the head the stockwill move upward from the lowermost position and be operated upon inturn by the roughing tool, then the finishingtool, and then it will passover the top and downward at the rear, so as to be operated upon by theup er or first die and finally the lower or secon die, after which thefinished screw is severed and the spindle reaches the bottom positionagain, where the stock is fed forward for a new operation. derstood thatwhile the empty lowermost spindle is being filled or the stock thereinfed forward against the stop, the tools and dies are performing theirwork on the other ma- It will be unterial, and also that the new stockis not supplied or fed forward until the finished screw has been cutoff. In order to have this work performed, the spindle-driving mechanismabove described is rotating the five spindles at the required s eed, but`the fact that it rotates the spind e through which the new stock isbeing fed is not detrimental to the successful operation of my machine.

The cam is of such size and its groove 101 so shaped that after thefinished screw has been severed at the rear of the machine and themechanism above described has turned the head 34 to bring the stock fromwhich the screw was cut to the lowermost position, the feed of the stockcommences and the cam, through the lever 103, simultaneously movesforward the die spindle. During this forward movement the roughingtooloperates on the stock which has last been fed forward, and the finishingtool operates on the material which has last been roughened, and just atthe moment when these two tools have finished their work the stopstrikes the projected extremity of the new piece of stock and the feedof the latter terminates, while the groove in the cam 100 has done itscomplete work yand the retraction of the tool slide now commences. Itisquite obvious that the cam groove may be so shaped as to cause thisretraction to be more speedy than the forward movement. When thesemembers have resumed their original position, the head 34 is turnedforward one additional step, which obviously carries the first piece ofmaterial whose turning is finished over to the rear lof the machineready to be treated by the first die and necessarily moves the roughenedpiece of material up into position for operationby the finishing tool.

Having explained the manner of operating the head 34, of feeding thestock, and of roughing and finishing the body vof the screw being vmade,it remains only to cut the thread thereon, and this is accomplished by adie of the usual construction which is mounted in the holder 122. It isto be understood that as the finished .material has passed over the topof the machine, it is op erated on by the die.V Beginning with the partsabout in the position shownY in Fig. 2, as .the cam 111 strikes theroller 112 the lever 113 moves the fork 116 to the right and thisdisengages the clutch member 128 splined on the spindle from the member134 which is rapidly and constantly rotated by the drum 133, therebychecking the positive and rapid rotation of the spindle. rihe loosenessof the hook 127 in the groove of the hub 126 permits the member 1.28 tostrike the hub so that gear 15() and sleeve 123 and its head 124 arealso moved to the right. This permits spring 154 to expand and long gear151 to slide on the shaft 131 toward the collar 155. As soon as the pins143 on the head and holder engage, the spindle commences to moveforward; and when the mouth of the die engages the rotating stock, theturning of the latter tends to more tightly engage the inclined faces ofsaid pins. This. causes the spindle, head, sleeve, and gear 150 torevolve in the same direction and speed as the live spindle until theretarding device comes into play as the ratchets 156 engage, after whichthese parts will revolve more slowly than said live spindle because ofthe relative size of the enaging gears 151 and 150-the speed of the'ormer being limited to that of the shaft 131 and the gear 150 and itsconnected parts rotating at about half that speed. Meanwhile the collar138 has moved the gear 134 along on the drum 133, and the collar 141 hascompressed the spring 14() against the left standard 118. The parts nowstand in the position shown in Fig. 3. Just at this time the roller 112passes off cam 111, and the spring 120 would return the parts to theposition shown in Fig. 2 if it were not for the clinging engagements ofthe pins 143. The pitch of the thread within the die now draws thelatter forward and the pins 143 also draw all arts forward until thethread of the screw is finished. Just at this time gear 150 strikesforward standard 118, or a stop 145 therein, and further forwardmovement of the die holder forcibly disenga es the pins 143, and the diecontinues to revo ve with the screw being made. The spring 120 nowreturns the clutch member 128 and connected parts to the left,which'causes the gear 150, by engaging the shoulder 152, to compress thes ring 154 and move the long gear 151 to the eft. rlhis causes theratchet ,teeth 156 to be disengaged and said member 128 to rengage withthe rapidly rotating gear 134, and the latter causes an acceleratedrotation of the spindle and die in the same direction as that of thelive spindle so that the die is drawn off of the screw just finished andall parts returned to the position shown in Fig. 2. Not only is thisarrangement simpler than in my previous patent above referred to but itaccomplishes a gain in the speed of the machine, because as the die isrun more slowly the machine can be run more rapidly-thus increasing theoutput.

What is claimed as new is:

11 InV a screw-making machine, the combination with the liveanddie-spindles, a clutch member splined on the latter, a second clutchmember loose thereon, a power shaft, and gearing between it and saidsecond member for rotating the latter faster than said shaft; of asleeve loose `on the spindle, clutch pins between the sleeve andspindle., means for moving said first member and sleeve forward andbackward to alternately engage and disengage the two clutches, a largegear fast on the sleeve, a smaller gear engaging it and loose on theshaft, and connections between said gear and shaft for limiting therotation of the small gear to that of the shaft after the saidfirst-mentioned clutch members have disengaged.

2. In a screw-,making machine, the c0mbination with the liveanddie-spindles, a clutch member splined on the latter, a second clutchmember loose thereon, a power shaft, and gearing between it and saidsecond member for rotating the latter constantly; of a sleeve loose onthe spindle, clutch pins between the sleeve and spindle, means formoving said first member and sleeve forward and backward to alternatelyengage and disengage the two clutches, a large gear fast on the sleeve,a smaller gear engaging it and loose on the shaft, a collar fast on theshaft, ratchet teeth on adjacent faces of said collar and small gear,and mechanism for engaging said teeth after said first-mentioned clutchmembers have disengaged.

3. In a screw-making maohine,'the combination with the liveanddie-spindles, a clutch member splined on the latter, a second clutchmember loose thereon, a power shaft, and driving gearing between it andsaid second member for rotating the latter constantly; of a sleeve looseon the spindle, clutch pins between the sleeve and spindle, means formoving said first member and sleeve forward and backward to alternatelyengage and disengage the two clutches, a large gear fast on the sleeve,a smaller gear engaging it and loose on the shaft, a collar fast on theshaft, ratchet teeth on adjacent faces of said collar and small gear,and a spring on the shaft between said driving gear and smaller gear forengaging said teeth after said first-mentioned clutch members havedisengaged. i

4. In a screw-making machine, the combination with the liveanddie-spindles, a clutch member splined on the latter, a second clutchmember loose thereon, a power shaft, and gearing between it and saidsecond member for rotating the latter constantly; of a sleeve loose onthe spindle, clutch pins between the sleeve and spindle, means formoving said first member and :sleeve forward and backward toEalternately engage the two clutches, `a .large gear lfast on thesleeve, a smaller gear engaging .it and loose on .the shaft, a=collarfast on the shaft, ratchet teeth in adjacent ends -oi said collar .andsmall gear, a shoulder at the 'other end of the latter, and .a springlpressing the shouldernormally against the rear side of Vthe large gearwhereby its forwardvmovement permits said teeth to `engage after saidfirst-mentioned -c-lutch members .have disengaged.

5. In a screw-making machine, the combination with the liveanddie-spindles, a ,clutch member splined on the latter, a second clutchmember lloose thereon, `a power shaft, `a driving gear mounted `thereonand having a pocket in one end, and teeth between it and said seoondmember for rotating the latter constantly of a sleeve loose `on thespindle, clutch ins between the sleeve eoagoi and spindle., :means formoving said rst member andfsleeve '.orwardfand baekwaird 4to alternatelyengage the two clutches, a large gear faston the sleeve, .a :smallerAgear fen gaging .it and loose on the shaft, a Collar fast on the shaft,ratchet 'teeth on .adj acent :ends of said collar .fand small gear, avshoulder at the other 4end of the latter .adapted Ito enter saidpoolet, and a spring coiled-ion .fthe power shaft within the pocket andpressing V.the shoulder normally .against 'the rear side of 'the largegear whereby its forward movement permits said teeth to engage .aftersaid firstmentioned clutch members have disengaged.

In testimony whereof .il have 'hereunto subsoribed my signature .thisthe 27 day of August, A. D. 1.907..

FRANK 0.. CUR'HS. Vitnesses z F. E. CURTISS, S. Oseoon

